From f86bbb7a71c5b0e53eac686788093adc4c8f797f Mon Sep 17 00:00:00 2001
From: Linus Groh <mail@linusgroh.de>
Date: Wed, 4 Aug 2021 23:04:43 +0100
Subject: [PATCH] LibJS: Implement
 Temporal.ZonedDateTime.prototype.epochNanoseconds

---
 .../Runtime/Temporal/ZonedDateTimePrototype.cpp   | 14 ++++++++++++++
 .../Runtime/Temporal/ZonedDateTimePrototype.h     |  1 +
 .../ZonedDateTime.prototype.epochNanoseconds.js   | 15 +++++++++++++++
 3 files changed, 30 insertions(+)
 create mode 100644 Userland/Libraries/LibJS/Tests/builtins/Temporal/ZonedDateTime/ZonedDateTime.prototype.epochNanoseconds.js

diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp
index aceb7cdfee..66de1dea54 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp
@@ -45,6 +45,7 @@ void ZonedDateTimePrototype::initialize(GlobalObject& global_object)
     define_native_accessor(vm.names.epochSeconds, epoch_seconds_getter, {}, Attribute::Configurable);
     define_native_accessor(vm.names.epochMilliseconds, epoch_milliseconds_getter, {}, Attribute::Configurable);
     define_native_accessor(vm.names.epochMicroseconds, epoch_microseconds_getter, {}, Attribute::Configurable);
+    define_native_accessor(vm.names.epochNanoseconds, epoch_nanoseconds_getter, {}, Attribute::Configurable);
 }
 
 static ZonedDateTime* typed_this(GlobalObject& global_object)
@@ -413,4 +414,17 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::epoch_microseconds_getter)
     return js_bigint(vm, move(us));
 }
 
+// 6.3.18 get Temporal.ZonedDateTime.prototype.epochNanoseconds, https://tc39.es/proposal-temporal/#sec-get-temporal.zoneddatetime.prototype.epochnanoseconds
+JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::epoch_nanoseconds_getter)
+{
+    // 1. Let zonedDateTime be the this value.
+    // 2. Perform ? RequireInternalSlot(zonedDateTime, [[InitializedTemporalZonedDateTime]]).
+    auto* zoned_date_time = typed_this(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. Return zonedDateTime.[[Nanoseconds]].
+    return &zoned_date_time->nanoseconds();
+}
+
 }
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.h b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.h
index cf73324e13..29d00168e2 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.h
@@ -34,6 +34,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(epoch_seconds_getter);
     JS_DECLARE_NATIVE_FUNCTION(epoch_milliseconds_getter);
     JS_DECLARE_NATIVE_FUNCTION(epoch_microseconds_getter);
+    JS_DECLARE_NATIVE_FUNCTION(epoch_nanoseconds_getter);
 };
 
 }
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Temporal/ZonedDateTime/ZonedDateTime.prototype.epochNanoseconds.js b/Userland/Libraries/LibJS/Tests/builtins/Temporal/ZonedDateTime/ZonedDateTime.prototype.epochNanoseconds.js
new file mode 100644
index 0000000000..83336f7625
--- /dev/null
+++ b/Userland/Libraries/LibJS/Tests/builtins/Temporal/ZonedDateTime/ZonedDateTime.prototype.epochNanoseconds.js
@@ -0,0 +1,15 @@
+describe("correct behavior", () => {
+    test("basic functionality", () => {
+        const timeZone = new Temporal.TimeZone("UTC");
+        const zonedDateTime = new Temporal.ZonedDateTime(1625614921000000000n, timeZone);
+        expect(zonedDateTime.epochNanoseconds).toBe(1625614921000000000n);
+    });
+});
+
+test("errors", () => {
+    test("this value must be a Temporal.ZonedDateTime object", () => {
+        expect(() => {
+            Reflect.get(Temporal.ZonedDateTime.prototype, "epochNanoseconds", "foo");
+        }).toThrowWithMessage(TypeError, "Not a Temporal.ZonedDateTime");
+    });
+});